1. Field of the Invention
This invention pertains to the preparation of noncellular polyurethane sealant compositions containing ethylene oxide adducts of toluenediamine.
2. Description of the Prior Art
Those skilled in the art know that polyurethane sealant compositions can be prepared by mixing a polyol with an inorganic filler and reacting the mixture with a polyisocyanate. U.S. Pat. Nos. 3,450,653 and 3,484,517 are two examples of patents which disclose this teaching. The sealants disclosed in the prior art, however, have limited utility because their physical properties, such as tensile strength, hardness, brittleness, heat distortion, impact strength, and shrinkage resistance, have values which, although desirable for some uses, make them undesirable for other uses.
This application relates to a method for preparing sealants which are strong, flexible, and have low shrinkage. The sealants are prepared by mixing polyoxyalkylene polyether glycol or polyether glycol blend with an ethylene oxide adduct of toluenediamine and triisopropanolamine. The mixture is reacted with a polyisocyanate to form the polyurethane sealant. The prior art does not disclose this combination of ingredients or the significance of the combination.